This time, we will turn the secondary combustion flame of Nafco Home Center's flame stove into a tornado. As for the product overview, it is made up of 4 parts and is used as a stove for heating and for cooking. This is the principle of secondary combustion. Primary combustion occurs inside the stove, and the air taken in from below is blown out from the top side, causing secondary combustion. This is a secondary combustion hole. The secondary combustion hole is 6mm x 6mm. That's it for the frame stove. This is a slightly larger frame stove L size. The secondary combustion hole is 10mm in diameter. I bent this hole with a tool. By bending the secondary combustion hole, we created a beautiful tornado. For this flame stove, we created a ring that allows the secondary combustion hole to be tornadoed without bending it. The ring is attached to the frame stove. Of course you can also remove it. Now let's make a tornado ring. The stainless steel version is 333mm x 400mm and 0.3mm thick. Draw lines with widths of 8mm, 6mm, 6mm, and 10mm. Apply masking tape to the secondary combustion hole. Mark on masking tape. Peel off the masking tape and attach it to the stainless steel plate. This is a chisel that I bought at a 100 yen shop. Make a cut in the stainless steel plate with a carving light. Sharpen the cutting edge from time to time. The cut with the chisel is completed. Drill a hole in the wood. Tap the notch in the stainless steel with a round stick. The processing of the stainless steel plate is complete. I'm going to tighten the screws. The screw size is M2 x 4mm. The tornado ring is completed. Assemble and disassemble frame stoves. Slide the ring to ratchet and find the optimal position. We will check the combustion. The fuel is pine pellets. Accelerate ignition with fuel alcohol. Secondary combustion has occurred, so attach the fire ring. There are 28 secondary combustion holes, but there are only about 10 flame lines. No matter how long it takes, the 28 flames will not appear and it will not turn into a beautiful tornado. The pillar of fire is barely rotating. Remove the fire ring and observe. In the combustion hole, a layer of air forms around the circumference and the flame coalesces. This is a secondary combustion stove that I previously DIYed. Air is released from each secondary combustion hole, creating a flame. There are as many flame lines as there are holes. A on the left is DIY, and the ideal direction is the air coming out of the secondary combustion hole. On the other hand, B is a tornado ring and the air coming out of the hole is right next to it, so a layer of air is created and the flames combine and rotate. The blue arrows in A and B are the direction of air. C widens the hole in the tornado ring as a countermeasure, making the air flow similar to A. This is the tornado ring before the hole is expanded. Enlarge the hole using a mini router. Let's make the handle for the tornado ring. The measures are complete. I widened the hole. This is the ring handle. Moving the ring changes the open area of the secondary combustion hole. We are planning to change the tornado by changing the secondary combustion hole. The ring can be put on and taken off relatively smoothly. But then something unexpected happened. I will check the combustion again. Now that the secondary combustion flame has appeared, attach the fire ring. This time, there are as many flames as there are holes. However, there is still a twist of flame, but it has not turned into a tornado. A tornado has occurred. Beautiful flame rotation. I tried to move the tornado ring, but it doesn't move at all. I gave up on the tornado variable. The tornado ring moved when it was cold, but when it got hot, the ring expanded due to the heat and stopped moving. I loosened the fit the first time and thought it was fine, but I need to loosen the fit further. That will be my next assignment. That's all for DIY tornado ring.
